its sounds like youve injured your rotator cuff along with you delt. this is common with people who train using bench presses and military presses. the muscle consists of 4 individual smaller muscles, so if proper form isnt followed its easy to strain or tear these muscles. if your worried about losing strength keep eating a high protien medium carb diet. this will really help keep all your strength. be sure to
ice the area at least 3times a day. be sure to rotate your arm in all directions a few times a day to keep range of motion. and i know it sucks but try to avoid doing movements that have ANY connection with your delt, its hard, but even heavy bicep curls can extend the time of recovery. try pushups before you start heavy benching again. look at it like this, its the perfect time to develop your midsection and lower body.
good luck!!